The development of a method to predict protection of a vaccine against HIV

12 September 2013

Unfortunately, to date, it is impossible to predict the efficacy of an experimental vaccine against HIV. Animal models play an important role in the development of an anti-HIV vaccine. These models are not only important for testing the efficacy of vaccine candidates, but also provide the opportunity to explore the mechanism of protection against disease.

The development of an (HIV) vaccine involves many steps. Ultimately, the vaccine will be tested on a limited scale in humans living in areas with a high prevalence of HIV, before it is implemented at a large scale. For the development of an effective HIV vaccine, protection against HIV infection must first be demonstrated. For ethical reasons, it is not possible to infect vaccinated humans with HIV, because, the subjects have to take anti-HIV drugs for prolonged periods of time (perhaps throughout their lives) in case the potential vaccine is not effective. Therefore, the efficacy of the vaccine candidate is first tested in an animal model. In these models, vaccinated animals are frequently exposed to (relatively) high doses of virus in order to determine whether the vaccine provides protection

During natural transmission, less amounts of virus will be present. Researchers at the BPRC have now used a sensitive test to quantify and study in detail the interaction of small numbers of viruses with immune cells and antibodies. This allowed them to detect effects of antibodies against the virus that had previously been unknown. By further optimizing and validating this type of test using the rhesus monkey model, they hope to eventually predict the efficacy of an anti-HIV vaccine in humans. The results of the first step in this direction have been published in the online magazine PlosOne.